Electron device

ABSTRACT

A driving unit for an electronic device including a planar voice coil, a resilient member, a support section moveably attached to a plate member of the electronic device by the resilient member, and a first magnet disposed inside the planar voice coil and a second magnet disposed outside the planar voice coil, wherein the first and second magnets are fixedly attached to the support section, wherein the plate member comprises a transparent central section and another section adjacent to the transparent central section, the plate member being moveably attached to the another section by the resilient member.

The present Application is a Continuation Application of U.S. patentapplication Ser. No. 09/988,681, filed on Nov. 20, 2001. With respect tothe prior co-pending U.S. application Ser. No. 09/988,681, thisContinuation Application incorporates the claim of priority fromJapanese Application No. 2000-361211, filed on Nov. 28, 2000, andclaimed under 35 U.S.C. §119. The present Application is assigned ofrecord to NEC Corporation at Reel 012316 and Frame 0484.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electronic device that is relativelysmall such as a portable radio terminal, and in particular, to anelectronic device comprising a speaker for audio output and a displayfor displaying information visually.

2. Description of the Related Art

Relatively small sized electronic devices, for example, a portableterminal etc. as typified by a cellular phone and a PHS (PersonalHandyphone System) are widely used. Such electronic device is generallyprovided with a speaker for conversation or for giving variousinstructions to the device by voice, and a display for displaying visualinformation such as characters and images.

Japanese Patent Application Laid-Open No. HEI5-191335 discloses acard-sized electronic device. FIG. 1 illustrates the device as anexample of a conventional electronic device. The electronic device 101is provided with a liquid crystal display (LCD) 102 at the approximatecenter of the front surface, and keys 103 and a flat speaker 104thereunder.

In addition, in Japanese Patent No. 2642530, there is disclosed aportable terminal that outputs audio information or image informationcorresponding to an ID cord from its speaker or display.

In the meanwhile, the more the device is downsized, the largerproportion of its front surface is occupied by the display part.

FIGS. 2 and 3 illustrate examples of electronic devices, which areportable terminals. The all-in-one portable terminal 111 shown in FIG. 2is provided with a display 113 and operation keys 114 on the frontsurface of its main body 112. In addition, a miniature speaker 115 and amicrophone 116 are disposed respectively on each end. Besides, thefolding portable terminal 121 shown in FIG. 3 is provided with a display123 and a speaker 124 at the upper side, and operation keys 125 and amicrophone 126 at the lower side with a hinge connection 122 at thecenter.

In both examples of FIGS. 2 and 3, the data displayed by the portableterminals 111 and 121 have been changing to the higher resolution imagesor larger volumes of text information. Consequently, it comes intoquestion that how the portion of spaces occupied with the displays 113and 123 is set for the relatively small-sized electronic devices underthe limitation on sizes. In the actual situation, spaces for thespeakers 115 and 124 are largely restricted in order to reserve thewider spaces for the displays 113 and 123.

On the other hand, in the electronic device provided with communicationfacilities such as the portable terminals 111 or 121, there areincreasing occasions of downloading music and other various data from aserver on the Internet, and accordingly, occasions of reproducing soundsuch as music etc. at its built-in speaker is also on the increase. Inthese circumstances, it is necessary to improve the sound quality of thespeakers 115 and 124. Therefore, there is a limit to the miniaturizationof the speakers 1 15 and 124, which is required to widen the displays113 and 123.

As above, problems have been concretely pointed out with respect to theconventional portable terminal. These are commonly observed in asmall-sized electronic device having a speaker and a display.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide anelectronic device in which accommodation space of a display can bewidened to the space where a speaker is disposed.

In accordance with the first aspect of the present invention, there isprovided an electronic device comprising: a main body, a displaydisposed at a prescribed position on the e main body for showinginformation visually, a transparent plate member provided on the surfaceof the display, and a driving means installed at a prescribed positionon the plate member for vibrating the plate member in response to anaudio signal.

That is, in the first aspect of the present invention, the transparentplate member provided on the surface of the display vibrates in responseto an audio signal to output sound. Consequently, the display can besituated even over the space where a speaker is supposed to be disposed,and thus obtaining a relatively large display.

In accordance with the second aspect of the present invention, anelectronic device comprises: a main body being slender in shape as ahand set, which has a microphone near the end of its front surface; adisplay disposed in a prescribed space, which includes a space where aspeaker is disposed, near the end opposite to the microphone on the mainbody for showing information visually; a transparent plate memberprovided on the surface of the display, and a driving means installed ata prescribed position on the plate member for vibrating the plate memberin response to an audio signal.

That is, in the second aspect of the present invention, the display issituated even over the space where the speaker is supposed to bedisposed on the slender shape hand set, and the transparent plate memberprovided on the surface of the display vibrates in response to an audiosignal to output sound. Consequently, a relatively large display can beobtained.

In accordance with the third aspect of the present invention, in thefirst or the second aspect, the driving means includes magnets and avoice coil where an audio signal is inputted, either of which isinstalled on the transparent plate member.

That is, in the third aspect of the present invention, the driving meansfor outputting sound is provided with the magnets and the voice coil.The magnets or the voice coil is installed on the transparent platemember to vibrate it, and thus enabling sound output.

In accordance with the fourth aspect of the present invention, in thefirst or the second aspect, the driving means are installed at pluralplaces on the transparent plate member.

That is, in the fourth aspect of the present invention, there may be oneor more driving means installed on the plate member. By installing thedriving means at plural places, it is possible to uprate sound outputand reduce accommodation space per a driving means.

In accordance with the fifth aspect of the present invention, in thefirst or the second aspect, the voice coil is a planar coil having ashape of a square frame. The magnets are disposed at placescorresponding to both inside and outside of the frame of the voice coilon an opposite spaced surface to the surface where the voice coil isinstalled.

That is, in the fifth aspect of the present invention, a planar coilhaving a shape of a quadrilateral frame is used as the voice coil. Themagnets are disposed at places corresponding to both inside and outsideof the frame of the voice coil on an opposite spaced surface to thesurface where the voice coil is installed, and thereby an audio signalis converted to vibrations of either/both of the surfaces.

In accordance with the sixth aspect of the present invention, in thefifth aspect, plural planar coils are built up in the directionorthogonal to the surface where the coils are installed.

That is, in the sixth aspect of the present invention, plural planarcoils are built up in the direction orthogonal to the surface where thecoils are installed, and thus allowing enough volume of sound to beoutputted.

In accordance with another aspect of the present invention, a drivingunit for an electronic device includes a planar voice coil, a resilientmember, a support section moveably attached to a plate member of theelectronic device by the resilient member, and a first magnet disposedinside the planar voice coil and a second magnet disposed outside theplanar voice coil, wherein the first and second magnets are fixedlyattached to the support section, wherein the plate member comprises atransparent central section and another section adjacent to thetransparent central section, the plate member being moveably attached tothe another section by the resilient member.

The present invention further comprises the planar voice coil comprisinga shape of a quadrilateral frame and the first and the second magnetsare quadrilateral shaped complementary to the shape of the planar voicecoil.

The present invention further comprises a second planar voice coiladjacent the planar voice coil in a direction orthogonal to a surface onwhich the planar voice coil is installed.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and features of the present invention will become moreapparent from the consideration of the following detailed descriptiontaken in conjunction with the accompanying drawings in which:

FIG. 1 is a plan view showing a conventional electronic device;

FIG. 2 is a plan view showing an example of a conventional portableterminal;

FIG. 3 is a plan view showing a conventional folding portable terminalhaving a hinge connection in its open state;

FIG. 4 is a front view of a portable terminal as an electronic deviceaccording to an embodiment of the present invention;

FIG. 5 is a back view of a display cover of the embodiment of FIG. 4;

FIG. 6 is a cross section view of a drive taken along the line A-A′ inFIG. 5;

FIG. 7 is a plan view showing a shape of a planar coil of theembodiment;

FIG. 8 is a cross section view taken along the line B-B′ in FIG. 6showing a physical relationship among the planar coil, the first magnetand the second magnet; and

FIG. 9 is a cross section view of a drive taken along the line A-A′ inFIG. 5 according to another embodiment of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

Referring now to the drawings, a description of preferred embodiments ofthe present invention will be given in detail.

FIG. 4 is a front view of a portable terminal as an electronic deviceaccording to an embodiment of the present invention. A portable terminal201 comprises a main body 202, a display/speaker section 203, anoperating section 204, and a microphone 205. The display/speaker section203 is located at the upper part of the front surface of the main body202. The operating section 204 is disposed beneath the display/speakersection 203, similarly to the conventional portable terminal shown inFIG. 2, and further, the microphone 205 is disposed thereunder.According to this embodiment, as is described above, a display and aspeaker are united and form the display/speaker section 203. Thedisplay/speaker section 203 is provided with a display cover 206 infront thereof for protecting the surface of its LCD (liquid crystaldisplay).

FIG. 5 is a back view of the display cover. The display cover 206comprises a transparent part 211 and a colored part 212 that is arrangedso as to surround the transparent part 21 1. The transparent part 211corresponds to a liquid crystal panel (not shown), and protects thepanel from external damages while retaining the display on the panel.The colored part 212 may be made of the same flat sheet material as thetransparent part 211, however, it is colored in order to visuallydistinguish between a display area and other areas on the liquid crystalpanel.

The colored part 212 is provided with a drive 213 that vibrates thedisplay cover 206 to output sound. A pair of driving signal wires 214and 215 extends from the drive 213.

FIG. 6 is a section of the drive 213 taken along the line A-A′ in FIG.5. The drive 213 includes first and second supporting sections 221 and223, absorbers 222, a planar coil 226, and first and second magnets 231and 232. The plate supporting section 221 is fixed on the colored part212, and supports the second supporting section 223 with the absorbers222. There is a small space left between the first and second supportingsections 221 and 223. The absorbers 222 are made of elastic material,and thereby the second supporting section 223 can reciprocate withrespect to the first supporting section 221 in the directions indicatedby arrow 225. On the first supporting section 221, the planar coil 226winding in a spiral is installed.

FIG. 7 illustrates the shape of the planar coil. The planar coil 226 iswound to form a rectangular frame so as to be efficiently disposed onthe colored part 212 shown in FIG. 5. Each end of the planar coil 226 iselectrically connected to one end of the respective driving signal wires214 and 215.

FIG. 8 is a section taken along the line B-B′ in FIG. 6 showing aphysical relationship among the planar coil, the first magnet and thesecond magnet. The first magnet 231 and the second magnet 232 arelocated at positions opposed to, but avoiding the planar coil 226 on thesecond supporting section 223 shown in FIG. 6. The first magnet 231 islocated so that its tip fits in a space 235 within the frame of theplanar coil 226. The second magnet 232 is arranged a little outside theoutmost circumference of the planar coil 226.

Consequently, when an audio signal is applied via a pair of the drivingsignal wires 214 and 215, a magnetic field is generated in the planarcoil 226. Subsequently, the first and second supporting sections 221 and223 repeatedly come close to and away from each other under theinteraction between the magnetic field and magnetic fields of the firstand second magnets 231 and 232 according to Fleming's law. Thus thedisplay cover 206 vibrates while resonating.

As is described above, an audio signal outputted from an amplifier (notshown) is applied to the planar coil 226 via the driving signal wires214 and 215, and thereby sound is outputted from the whole display cover206. Namely, a portable terminal according to the present invention doesnot need to have sound output holes for a speaker as well as a speakerprovided on the front surface differently from a conventional one.

Incidentally, in the description of this embodiment, the secondsupporting section 223 is supported by the first supporting section 221.Instead, the second supporting section 223 may be fixed on an immobilemember (not shown), and the first supporting section 221 may beelastically supported by the absorbers 222.

FIG. 9 illustrates another embodiment of the present invention, andcorresponds to FIG. 6 in the above embodiment. In FIG. 9, the likecomponents are designated by the like reference numerals as in FIG. 6,and explanation thereof will be omitted. In this embodiment, a planarcoil 301 having the same shape as the planar coil 226 shown in FIG. 7 isdirectly fixed on the colored part 212 as a substitute for the firstsupporting section 221 shown in FIG. 6.

The planar coil 301 is provided with a plate insulation 302 having aframe shape equal in size to the coil 301 on the surface facing to thesecond supporting section 223. In addition, the same planar coil 226 inthe previous embodiment is installed on the insulation 302 to thesurface facing the second supporting section 223. In this manner, twoplanar coils 301 and 226, and the insulation 302 are installed so as toform the tri-layer structure, and have a space in the center similarlyto the previous embodiment. Each end of the planar coil 226 iselectrically connected to each end of the planar coil 301 through theinsulation 302 by conducting wires 303 and 304. Accordingly, electriccurrent is passed through in the same direction at both planar coils 226and 301.

As is the case with the previous embodiment, the first and secondmagnets 231 and 232 are disposed on the second supporting section 223.The structure is identical to that of the previous embodiment.Therefore, in a portable terminal of this embodiment, a strongermagnetic field is produced due to the addition of the planar coil 301 tothe planar coil 226. As a result, the display cover 206 vibrates bydriving force stronger than that applied in the previous embodiment inrelation to the magnets 231 and 232. Thus larger volume of sound isoutputted.

While planar coils have three layers with an insulation between them inthis embodiment, more coils may be added to the layers withinterstratifing insulations. Moreover, the coil may be wound around abobbin disposed perpendicular to the display cover 206. Besides,although the drive part 213 is located at a side of the display cover206 in the above embodiments, it is a matter of course that a drive maybe installed at any position on a display cover. Furthermore, while adescription has been given about a portable terminal in the aboveembodiments, the present invention is naturally applicable to otherelectronic devices.

As set forth hereinabove, in accordance with the present invention, atransparent plate member provided on the surface of a display vibratesin response to an audio signal to output sound. Consequently, thedisplay can be situated even over the space where a speaker is supposedto be disposed, and thus permitting a relatively large display. Inaddition, there is no need to provide a portable terminal with soundoutput holes for a speaker, and therefore it is possible to improve thedamp proof effect.

Moreover, in accordance with an aspect of the present invention, drivingmeans are installed at plural places on the plate member, and thereforeit is possible to uprate sound output and reduce accommodation space pera driving means.

Furthermore, in accordance with another aspect of the present invention,plural planar coils are built up in the direction orthogonal to thesurface where the coils are installed, and thus enough volume of soundcan be outputted.

While the preferred embodiments of the present invention have beendescribed using specific terms, such description is for illustrativepurposes only, and it is to be understood that changes and variationsmay be made without departing from the spirit or the scope of thefollowing claims.

1. A driving unit for an electronic device, comprising: a planar voicecoil; a resilient member; a support section moveably attached to a platemember of said electronic device by said resilient member; and a firstmagnet disposed inside said planar voice coil and a second magnetdisposed outside said planar voice coil, wherein the first and secondmagnets are fixedly attached to said support section, wherein said platemember comprises a transparent central section and another sectionadjacent to the transparent central section, said plate member beingmoveably attached to said another section by said resilient member.
 2. Adriving unit for an electronic device according to claim 1, wherein saidplanar voice coil comprises a shape of a quadrilateral frame and saidfirst and said second magnets are quadrilateral shaped complementary tosaid shape of said planar voice coil.
 3. A driving unit for anelectronic device according to claim 1, further comprising a secondplanar voice coil adjacent said planar voice coil in a directionorthogonal to a surface on which said planar voice coil is installed.